Category

Published on

15 Oct 2008

Abstract

Since its discovery by von Laue in 1912, X-ray diffraction has become an indispensable tool for
structure determinations in the physical and biological sciences. X-rays are characterized by high
energies and by wavelengths that are commensurate with nanometer-sized structures – unlike
optical probes, whose wavelengths are several orders of magnitude larger. Additionally, X-rays
couple only weakly with matter, and the refractive indices of X-rays differ only slightly from
unity. The interactions of X-rays with solids thus follow the “Goldilocks principle” (not too
strong, not too weak, but just right) and are well suited for the analysis of nanostructured and
thin film materials. This talk will focus on key applications of a variety of X-ray analytical
methods in nanotechnology research and development. In advanced semiconductor device
fabrication, for instance, parameters such as thickness, density, and interfacial roughness are
critical to the performance of ultra-thin polycrystalline films and are routinely measured by X-
ray reflectometry, while strain and composition in advanced single crystal structures rely on high
resolution double- and triple-axis diffraction methods. Other X-ray techniques (such as texture
analysis, grazing incidence diffraction, small-angle scattering, and diffuse scattering) have
important application to nanomaterials characterization and will be discussed. The overarching
goal of this talk will be to illustrate the wide applicability of X-ray methods in current nanoscale
materials research.